The present invention relates to the microbial decontamination and medical equipment maintenance arts. It finds particular application in conjunction with counting a number of strong oxidant sterilization cycles to which medical (including dental and surgical) equipment has been subjected and will be described with particular reference thereto. However, it is to be appreciated that the invention will also find application in conjunction with monitoring the number of times that mortuary, laboratory, and other equipment have been sterilized or disinfected, monitoring other processing cycles of both medical and non-medical equipment, and the like.
Sterilizing or disinfecting equipment subjects articles to an environment which kills microbes. Common sterilizers include a steam autoclave which subjects the items to a combination of high temperature and pressure. Ethylene oxide gas sterilizers subject the items to reactive, ethylene oxide gas. Liquid sterilizers treat the items with a liquid solution that includes a reactive component, such as a strong oxidant.
Not all regularly sterilized medical instruments are made of materials which are substantially immune to the high temperature and pressure of a steam autoclave. Many instruments have plastic or rubber components which cannot withstand the thermal and pressure stresses of a steam autoclave. These items are typically sterilized using low temperature fluid (gas or liquid) sterilization systems.
Many instruments are rated to have a limited useful life. One scale for measuring the useful life is the number of sterilization cycles. After a preselected number of sterilization cycles, the instrument no longer has an assured functionality and should be discarded or rebuilt.
The loss of assured functionality may be attributable to various causes including dulling of cutting edges, potential misalignment of parts or wobble in joints, degradation of parts, particularly plastic and rubber parts, from use or the microbial decontamination processing or the like. The high temperatures of steam sterilization or reaction with gas or liquid sterilants may degrade some plastic and rubber parts. Such plastic and rubber components may cumulatively become bleached, brittle, or tacky.
Heretofore, difficulty was encountered in determining whether the functionality of the instruments was compromised. Degradation of internal parts is not readily determined by visual observation. Some degradation, such as becoming brittle or dull is hard for a human observer to gauge. Various techniques have been tried, but each has significant drawbacks. Periodic disassembly is time consuming and is not available for all instruments. Counting the number of use/sterilization cycles is often unreliable, particularly when there are multiple users and multiple copies of each instrument. Inventory control and purchase date monitoring does not provide a reliable indication of the number of use and sterilization cycles.
The present invention provides a new and improved technique for monitoring the number of use/sterilization cycles to which an instrument is subjected.